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organization has a different facility code and their card set also increments from 1. Thus different organizations can have card sets with the same card numbers but since the facility codes differ, the cards only work at one organization. This idea worked fine for a while but there is no governing body controlling card numbers, different manufacturers can supply cards with identical facility codes and identical card numbers to different organizations. Thus there is a problem of duplicate cards. To counteract this problem some manufacturers have created formats beyond 26 bit
Wiegand that they control and issue to an organization.
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was used in early access cards. This method was abandoned in favor of other proximity technologies. The new technologies retained the
Wiegand upstream data so that the new readers were compatible with old systems. Readers are still called Wiegand but no longer use the Wiegand effect. A Wiegand reader
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A common proximity format is 26 bit
Wiegand. This format uses a facility code, also called a site code. The facility code is a unique number common to all of the cards in a particular set. The idea is an organization has their own facility code and then numbered cards incrementing from 1. Another
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that makes access control decisions based on information about the credential. If the credential is included in an access control list, the access control system unlocks the controlled access point. The transaction is stored in the system for later retrieval; reports can be generated showing the
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In the 26 bit
Wiegand format bit 1 is an even parity bit. Bits 2-9 are a facility code. Bits 10-25 are the card number. Bit 26 is an odd parity bit. Other formats have a similar structure of leading facility code followed by card number and including parity bits for error checking.
118:. The integrated circuit outputs the card number to the coil which transmits it to the reader. The transmission of the card number happens in the clear—it is not encrypted. With basic understanding of radio technology and of card formats, Wiegand proximity cards can be hacked.
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can be used to counteract the problems of transmitting card numbers in the clear and control of the card numbers by manufacturers. Smart cards can be encoded by organizations with unique numbers and the communication between card and reader can be
93:. This number is usually called the facility code and is programmed by the administrator. The number is sent to an access control system, a
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Access badges use various technologies to identify the holder of the badge to an access control system. The most common technologies are
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110:. When a card is presented to the reader, the reader's electrical field excites a coil in the card. The coil charges a
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radiates a 1" to 5" electrical field around itself. Cards use a simple
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Southern Utah
University in View, Fall 2004, Alumni Awards, pages 3-4
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date/time the card was used to enter the controlled access point.
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A private security officer with an access card/ID card
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The access badge contains a number that is read by a
82:. The magnetic stripe ID card was invented by
44:used to gain entry to an area having automated
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59:, parking gates or other barriers.
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242:Physical Security Professional
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114:and in turn powers an
51:. Entry points may be
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202:IP video surveillance
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257:Security engineering
237:Photo identification
227:Magnetic stripe card
305:2011-10-27 at the
162:Common Access Card
116:integrated circuit
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24:Common Access Card
262:Security lighting
232:Optical turnstile
167:Computer security
80:biometric devices
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222:Logical security
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307:Wayback Machine
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197:ID card printer
182:Electronic lock
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95:computer system
64:magnetic stripe
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84:Forrest Parry
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217:Lock picking
212:Locksmithing
157:Card printer
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78:and various
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49:entry points
38:access badge
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324:Identifiers
130:Smart cards
91:card reader
76:smart cards
20:An example
288:References
277:Swipe card
272:Smart card
172:Credential
152:Biometrics
108:LC circuit
86:in 1960.
57:turnstiles
42:credential
135:encrypted
112:capacitor
68:proximity
318:Category
303:Archived
252:Security
207:Keycards
141:See also
192:ID Card
72:barcode
53:doors
40:is a
101:The
36:An
22:DoD
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137:.
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